Battery module and method for cooling the battery module

ABSTRACT

A battery module and a method for cooling the battery module are provided. The battery module includes a housing having an electrically non-conductive oil disposed therein, and a battery cell disposed in the housing that contacts the electrically non-conductive oil. The battery module further includes first and second heat conductive fins disposed in the housing that contacts the electrically non-conductive oil. The first and second heat conductive fins extract heat energy from the electrically non-conductive oil. The battery module further includes first and second conduits extending through the first and second heat conductive fins, respectively. The first and second conduits receive first and second portions of a fluid, respectively, therethrough and conduct heat energy from the first and second heat conductive fins, respectively, into the fluid to cool the battery cell.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 12/511,552 filed on Jul. 29, 2009, the entire contents of whichare hereby incorporated by reference herein.

TECHNICAL FIELD

This application relates to a battery module and a method for coolingthe battery module.

BACKGROUND OF THE INVENTION

In a typical air-cooled battery pack, ambient air from ambientatmosphere is directed across battery cells in the battery pack and issubsequently exhausted from the battery pack. However, the typicalair-cooled battery pack has a major challenge in maintaining atemperature of the battery pack within a desired temperature range.

In particular, a maximum operating temperature of the battery cells canoften be less than a temperature of ambient air utilized to cool thebatteries. In this situation, it is impossible to maintain the batterycells within a desired temperature range in an air-cooled battery pack.

Accordingly, the inventors herein have recognized a need for an improvedbattery module and a method for cooling the battery module thatminimizes and/or eliminates the above-mentioned deficiency.

SUMMARY OF THE INVENTION

A battery module in accordance with an exemplary embodiment is provided.The battery module includes a housing having an electricallynon-conductive oil disposed therein. The battery module further includesa battery cell disposed in the housing that contacts the electricallynon-conductive oil. The battery module further includes first and secondheat conductive fins disposed in the housing that contacts theelectrically non-conductive oil. The first and second heat conductivefins are configured to extract heat energy from the electricallynon-conductive oil. The battery module further includes first and secondconduits extending through the first and second heat conductive fins,respectively. The first and second conduits are configured to receivefirst and second portions of a fluid, respectively, therethrough and toconduct heat energy from the first and second heat conductive fins,respectively, into the fluid to cool the battery cell.

A method for cooling a battery module in accordance with anotherexemplary embodiment is provided. The battery module has a housing, abattery cell, first and second heat conductive fins, and first andsecond conduits extending through the first and second heat conductivefins, respectively. The method includes conducting heat energy from thebattery cell into an electrically non-conductive oil disposed in thehousing. The method further includes conducting heat energy from theelectrically non-conductive oil into the first and second heatconductive fins disposed in the housing. The method further includesreceiving first and second portions of a fluid in the first and secondconduits, respectively, and conducting heat energy from the first andsecond heat conductive fins, respectively, into the fluid to cool thebattery cell in the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic of a battery system having a battery module inaccordance with an exemplary embodiment;

FIG. 2 is a schematic of the battery module utilized in the batterysystem of FIG. 1 in accordance with another exemplary embodiment;

FIG. 3 is another schematic of the battery module of FIG. 2;

FIG. 4 is another schematic of the battery module of FIG. 2;

FIG. 5 is a schematic of a plurality of heat conductive fins utilized inthe battery module of FIG. 2;

FIG. 6 is an enlarged schematic of a portion of the heat conductive finsutilized in the battery module of FIG. 2;

FIG. 7 is another schematic of the battery module of FIG. 2;

FIG. 8 is a flowchart of a method for cooling the battery module in thebattery system of FIG. 1 in accordance with another exemplaryembodiment; and

FIG. 9 is a schematic of another battery system in accordance withanother exemplary embodiment.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Referring to FIGS. 1-3, a battery system 10 for generating electricalpower in accordance with an exemplary embodiment is illustrated. Thebattery system 10 includes a battery module 20, a compressor 22, acondenser 24, conduits 28, 30, 32, a temperature sensor 36, a fan 38,and a microprocessor 40. An advantage of the battery module 20 is thatthe battery module utilizes a non-conductive oil to transfer heat energyfrom a battery cell to at least one heat conductive fin to effectivelycool the battery cell.

For purposes of understanding, the term “fluid” means either a liquid ora gas. For example, a fluid can comprise either a coolant or arefrigerant. Exemplary coolants include ethylene glycol and propyleneglycol. Exemplary refrigerants include R-11, R-12, R-22, R-134A, R-407Cand R-410A.

Referring to FIGS. 4-6, the battery module 20 is provided to generate avoltage therein. The battery module 20 includes a housing 60, batterycells 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102,104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130,132, 134, 136, 138, 140, 142, 144 and 146, heat conductive fins 170,172, 174, 176, 178, 180, 182, 184, 186, 188, 190 192, 194, 196, 198,200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226,228, 230, 232, 234, 236, 238, 240, 242 and 244, conduit 250, heatconductive fins 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290292, 294, 296, 298, 300, 302, 304, 306, 308, 310, 312, 314, 316, 318,320, 322, 324, 326, 328, 330, 332, 334, 336, 338, 340, 342 and 344,conduit 350, and a non-conductive fluid 360.

Referring to FIG. 2, the housing 60 includes a lower housing portion 370and a lid (not shown) that is fixedly coupled to a top portion of thelower housing portion 370. In one exemplary embodiment, the lid issealed to the lower housing portion 370 such that the non-conductivefluid 360 is maintained within the lower housing portion 370 withoutleaking therefrom. In one exemplary embodiment, the lid and the lowerhousing portion 370 are constructed from plastic.

Referring to FIGS. 4 and 7, the battery cells 72, 74, 76, 78, 80, 82,84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114,116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142,144 and 146 are provided to generate an electrical voltage. Inparticular, each of the battery cells has a substantially similarstructure. For example, referring to battery cell 72, the battery cellincludes a body portion 380, flange portions 382, 384 and a pair ofelectrodes extending upwardly from the body portion 380. The flangeportions 382, 384 extend from first and second ends of the body portion380. Each pair of electrodes extending from each battery cell has avoltage therebetween. The electrodes of the battery cells can beelectrically coupled together either in series or in parallel dependingupon a desired voltage and current of the battery module 20. The batterycells are stacked proximate to one another within the lower housingportion 370. In one exemplary embodiment, each battery cell is alithium-ion battery cell. In alternative embodiments, the battery cellscould be nickel-cadmium battery cells or nickel metal hydride batterycells for example. Of course, other types of battery cells known tothose skilled in the art could be utilized.

Referring to FIGS. 4 and 6, the heat conductive fins 170, 172, 174, 176,178, 180, 182, 184, 186, 188, 190 192, 194, 196, 198, 200, 202, 204,206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232,234, 236, 238, 240, 242 and 244 are provided to conduct heat energy fromthe electrically non-conductive oil 360 and the battery cells into theheat conductive fins. The conduit 250 extends through apertures of theheat conductive fins 170, 172, 174, 176, 178, 180, 182, 184, 186, 188,190 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216,218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242 and 244and is brazed or welded to the heat conductive fins. Further, the heatconductive fins 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218,220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242 and 244 aredisposed in the housing 60 proximate to first ends of the battery cells72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104,106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132,134, 136, 138, 140, 142, 144 and 146, respectively. The heat conductivefins are constructed from at least one of aluminum and copper. Duringoperation, the conduit 250 is configured to receive a fluid at a firstend from the compressor 22. The conduit 250 conducts heat energy fromthe heat conductive fins into the fluid flowing therethrough to cool theelectrically non-conductive oil and the battery cells. The conduit 250is constructed from at least one of aluminum and copper. In oneexemplary embodiment, the heat conductive fins are triangular-shapedsheets. Of course, the heat conductive fins could have other shapesknown to those skilled in the art. In one exemplary embodiment, thefluid is a coolant such as ethylene glycol or propylene glycol forexample. In another exemplary embodiment, the fluid is a refrigerant.

Referring to FIGS. 4, 5, and 6, the heat conductive fins 270, 272, 274,276, 278, 280, 282, 284, 286, 288, 290 292, 294, 296, 298, 300, 302,304, 306, 308, 310, 312, 314, 316, 318, 320, 322, 324, 326, 328, 330,332, 334, 336, 338, 340, 342 and 344 are provided to conduct heat energyfrom the electrically non-conductive oil 360 and the battery cells intothe heat conductive fins. The conduit 350 extends through apertures ofthe heat conductive fins 270, 272, 274, 276, 278, 280, 282, 284, 286,288, 290 292, 294, 296, 298, 300, 302, 304, 306, 308, 310, 312, 314,316, 318, 320, 322, 324, 326, 328, 330, 332, 334, 336, 338, 340, 342 and344 and is brazed or welded to the heat conductive fins. Further, theheat conductive fins 270, 272, 274, 276, 278, 280, 282, 284, 286, 288,290 292, 294, 296, 298, 300, 302, 304, 306, 308, 310, 312, 314, 316,318, 320, 322, 324, 326, 328, 330, 332, 334, 336, 338, 340, 342 and 344are disposed in the housing 60 proximate to second ends of the batterycells 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102,104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130,132, 134, 136, 138, 140, 142, 144 and 146, respectively. The conduit 350is configured to receive a fluid at a first end from the compressor 22.The heat conductive fins are constructed from at least one of aluminumand copper. In one exemplary embodiment, the heat conductive fins aretriangular-shaped sheets. Of course, the heat conductive fins could haveother shapes known to those skilled in the art. During operation, theconduit 350 conducts heat energy from the heat conductive fins into thefluid flowing therethrough to cool the electrically non-conductive oiland the battery cells. The conduit 350 is constructed from at least oneof aluminum and copper. In one exemplary embodiment, the fluid is acoolant such as ethylene glycol or propylene glycol for example. Inanother exemplary embodiment, the fluid is a refrigerant.

The combination of the heat conductive fins 170, 172, 174, 176, 178,180, 182, 184, 186, 188, 190 192, 194, 196, 198, 200, 202, 204, 206,208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234,236, 238, 240, 242, 244 and the conduit 250, and the combination of theheat conductive fins 270, 272, 274, 276, 278, 280, 282, 284, 286, 288,290 292, 294, 296, 298, 300, 302, 304, 306, 308, 310, 312, 314, 316,318, 320, 322, 324, 326, 328, 330, 332, 334, 336, 338, 340, 342, 344 andthe conduit 350 can maintain the battery cells within a desiredtemperature range, and in particular can maintain the battery cells at atemperature less than a threshold temperature level. In one exemplaryembodiment, the desired temperature range is 15° Celsius-35° Celsius. Inanother exemplary embodiment, the threshold temperature level is 40°Celsius.

Referring to FIG. 6, the non-conductive oil 360 is disposed in thehousing 60 and contacts the battery cells to absorb heat energy from thebattery cells. In one exemplary embodiment, the electricallynon-conductive oil is mineral oil. Of course, other types ofelectrically non-conductive fluids known to those skilled in the artcould be utilized instead of the electrically non-conductive oil.

Referring again to FIG. 1, the compressor 22 is configured to pump arefrigerant through the conduit 28 into the conduits 250, 350 of thebattery module 20 in response to a control signal from themicroprocessor 40. The conduit 30 is also fluidly coupled to theconduits 250, 350 of the battery module 20. The conduit 30 receivesrefrigerant from the conduits 250, 350 and routes the refrigerant to thecondenser 24.

The condenser 24 is provided to extract heat energy from the refrigerantflowing therethrough to cool the refrigerant. As shown, a conduit 32 isfluidly coupled between the condenser 24 and the compressor 22. Afterexiting the condenser 24, the refrigerant is pumped through the conduit32 to the compressor 22.

The temperature sensor 36 is provided to generate a signal indicative ofa temperature level of the electrically non-conductive oil 360 disposedin the housing 60 that is received by the microprocessor 40. The signalfrom the temperature sensor 36 is further indicative of a temperaturelevel of the battery cells.

The fan 38 is provided to urge air past the condenser 24 to cool thecondenser 24 in response to a control signal from the microprocessor 40.As shown, the fan 38 is disposed proximate to the condenser 24.

The microprocessor 40 is provided to control operation of the batterysystem 10. In particular, the microprocessor 40 is configured togenerate a control signal for inducing the compressor 22 to pumprefrigerant through the battery module 20 when the signal from thetemperature sensor 36 indicates a temperature level of the electricallynon-conductive oil is greater than a predetermined temperature level.Further, the microprocessor 40 is configured to generate another controlsignal for inducing the fan 38 to blow air across the condenser 24 whenthe signal from the temperature sensor 36 indicates the temperaturelevel of the electrically non-conductive oil is greater than thepredetermined temperature level.

Referring to FIG. 8, a flowchart of a method for cooling the batterymodule 20 having a battery cell will now be explained. For purposes ofsimplicity, only one battery cell and two heat conductive fins in thebattery module 20 will be described.

At step 390, the heat energy from the battery cell 72 is conducted intothe electrically non-conductive oil 360 disposed in the housing 60.

At step 392, the heat energy from the electrically non-conductive oil360 is conducted into first and second heat conductive fins 170, 270disposed in the housing 60.

At step 394, first and second conduits 250, 350 receive first and secondportions of a fluid and conduct heat energy from the first and secondheat conductive fins 250, 350, respectively, into the fluid to cool thebattery cell 72 in the housing 60.

Referring to FIG. 9, a battery system 410 for generating electricalpower in accordance with another exemplary embodiment is illustrated.The battery system 410 includes a battery module 420, a pump 422, a heatexchanger 424, a cold plate 425, a reservoir 426, conduits 428, 430,431, 432, 434, a temperature sensor 436, a fan 437, a refrigerant system438, and a microprocessor 440. The primary difference between thebattery system 410 and the battery system 10 is that the battery system410 utilizes a coolant instead of a refrigerant to cool the batterymodule 420.

The battery module 420 has an identical structure as the battery module20 discussed above.

The pump 422 is configured to pump a coolant through the conduit 428into the battery module 420 in response to a control signal from themicroprocessor 440. As shown, the conduit 428 is fluidly coupled betweenthe pump 422 and the battery module 420, and the conduit 430 is fluidlycoupled between the battery module 420 and the heat exchanger 424. Afterexiting the battery module 420, the coolant is pumped through theconduit 430 to the heat exchanger 424.

The heat exchanger 424 is provided to extract heat energy from thecoolant flowing therethrough to cool the coolant. As shown, a conduit431 is fluidly coupled between the heat exchanger 424 and the cold plate425. After exiting the heat exchanger 424, the coolant is pumped throughthe conduit 431 to the cold plate 425.

The fan 437 is provided to urge air past the heat exchanger 424 to coolthe heat exchanger 424 in response to a control signal from themicroprocessor 440. As shown, the fan 437 is disposed proximate to theheat exchanger 424.

The cold plate 425 is provided to extract heat energy from the coolantflowing therethrough to further cool the coolant. As shown, a conduit422 is fluidly coupled between the cold plate 425 and the reservoir 426.After exiting the cold plate 425, the coolant is pumped through theconduit 432 to the reservoir 426.

The reservoir 426 is provided to store at least a portion of the coolanttherein. As shown, a conduit 434 is fluidly coupled between thereservoir 426 and the pump 422. After exiting the reservoir 426, thecoolant is pumped through the conduit 434 to the pump 422.

The temperature sensor 436 is provided to generate a signal indicativeof a temperature level of the electrically non-conductive oil, which isalso indicative of the temperature level of the battery module 420, thatis received by the microprocessor 440.

The refrigerant system 438 is provided to cool the heat exchanger 424 inresponse to a control signal from the microprocessor 440. As shown, therefrigerant system 438 is operably coupled to the cold plate 425.

The microprocessor 440 is provided to control operation of the batterysystem 410. In particular, the microprocessor 440 is configured togenerate a control signal for inducing the pump 422 to pump refrigerantthrough the battery module 420 when the signal from the temperaturesensor 436 indicates a temperature level of the electricallynon-conductive oil is greater than a predetermined temperature level.Further, the microprocessor 440 is configured to generate anothercontrol signal for inducing the fan 437 to blow air across the heatexchanger 424 when the signal from the temperature sensor 436 indicatesthe temperature level of the electrically non-conductive oil is greaterthan the predetermined temperature level. Further, the microprocessor440 is configured to generate another control signal for inducing therefrigerant system 438 to cool the cold plate 425 when the signal fromthe temperature sensor 436 indicates the temperature level of theelectrically non-conductive oil is greater than the predeterminedtemperature level.

The battery module and the method for cooling the battery module providea substantial advantage over other modules and methods. In particular,the battery module and the method provide a technical effect of coolinga battery cell in the battery module utilizing a non-conductive oil thatcontacts the battery cell in conjunction with a cooling manifold thatcools the non-conductive oil.

While the invention has been described with reference to exemplaryembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiments disclosed for carrying thisinvention, but that the invention will include all embodiments fallingwithin the scope of the appended claims. Moreover, the use of the terms,first, second, etc. are used to distinguish one element from another.Further, the use of the terms a, an, etc. do not denote a limitation ofquantity, but rather denote the presence of at least one of thereferenced items.

What is claimed is:
 1. A method for cooling a battery module, thebattery module having a housing, a battery cell, first and second heatconductive fins, and first and second conduits extending through thefirst and second heat conductive fins, respectively, the methodcomprising: conducting heat energy from the battery cell into anelectrically non-conductive oil disposed in the housing; conducting heatenergy from the electrically non-conductive oil into the first andsecond heat conductive fins disposed in the housing; and receiving firstand second portions of a fluid in the first and second conduits,respectively, and conducting heat energy from the first and second heatconductive fins, respectively, into the fluid to cool the battery cellin the housing.
 2. The method of claim 1, wherein the electricallynon-conductive oil comprises mineral oil.
 3. The method of claim 1,wherein the fluid comprises a coolant.
 4. The method of claim 3, whereinthe coolant comprises at least one of ethylene glycol and propyleneglycol.
 5. The method of claim 1, wherein the fluid comprises arefrigerant.